Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
386 FXUS64 KLIX 121108 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 608 AM CDT Tue May 12 2026 ...New AVIATION... .KEY MESSAGES... Updated at 604 AM CDT Tue May 12 2026 - Finally start to dry out Today as ridging builds into the area. Expect temperatures to increase again by mid to late week. - Some potential for fog development Wednesday morning due to clear skies, light winds and very wet ground. && .SHORT TERM... (Now through Thursday) Issued at 110 AM CDT Tue May 12 2026 Upper shortwave pretty much right on top of the area at midnight CDT. A northern stream shortwave was over the Dakotas, with an upper ridge over the Four Corners area. At the surface, the cold frontal boundary was over lower Plaquemines Parish, with high pressure over northern Arkansas. An area of mainly light rain was moving eastward along with the upper shortwave across the area. Temperatures were upper 60s to around 70 at midnight. The upper shortwave and any significant precipitation should be exiting the area by mid-morning. That is about the time we should start seeing breaks in the cloud cover, but we may not see full sunshine this afternoon. Wednesday and Thursday definitely look much better with nearly full sunshine, relatively light winds, and dew points in the 60s. That will keep humidities at a relatively comfortable level, even as high temperatures climb into the middle and upper 80s across the area. Overnight lows should be in the 60s in most areas. These temperatures are actually pretty close to normal for mid-May. && .LONG TERM... (Thursday night through Monday) Issued at 110 AM CDT Tue May 12 2026 At the start of the long term period, deep layer ridging will continue to be the dominant feature influencing the weather in the region. The resultant subsidence associated with this system will both warm and dry the mid and upper levels of the atmosphere, and this will keep a strong 2-3C 850mb temperature inversion in place for both Friday and Saturday. This inversion will effectively cap off deep updraft development each afternoon. At most, some fair weather cumulus activity will develop beneath the mid-level capping inversion. Temperatures will be quite warm as southerly flow off the Gulf increases overall low level humidity and the subsidence aloft induces warming throughout the atmospheric column. Afternoon highs will easily climb into the mid to upper 80s and heat index readings will rise into the lower 90s. Although humidity will be on the increase, dewpoints in the low to mid 60s will allow for decent overnight cooling and relief from the heat to occur. Sunday and Monday will see the ridge axis begin to shift to the east, and this will allow for slightly cooler temperatures to take hold in the mid and upper levels. There will still be a mid-level cap in place around 850mb, but it will weaken to around 1-2C. Given the strong daytime heating into the upper 80s and the development of a seabreeze each day, there should be sufficient low level convergence in place to overcome the capping inversion and fire off some isolated shower and thunderstorm activity both Sunday and Monday afternoon. If the updrafts in these storms get deep enough to allow for some dry air entrainment, a few wet microburst events could occur. This is supported by high downdraft CAPE values of 1000 to 1100 J/KG. The convection will be diurnally driven, so overnights will be dry and increasingly muggy as dewpoints rise into the upper 60s and lower 70s. Heat risk will rise into the moderate category for coastal locations by Monday due to these warmer overnight conditions. && .AVIATION... (12Z TAFS) Issued at 604 AM CDT Tue May 12 2026 Cloud deck around FL010 has been anywhere from SCT to OVC aqt most terminals this morning. With upper low gradually pulling away this morning, ceilings should be in the MVFR range by mid-morning and likely VFR this afternoon. Not out of the question some isolated showers could develop this afternoon, but don`t feel the threat is high enough to justify at a particular terminal at this time. The other concern will be for the potential development of fog at terminals around sunrise Wednesday due to clear skies, light winds and very wet ground. At this time, the only fog mention is at KMCB, but won`t rule it out anywhere. && .MARINE... Issued at 110 AM CDT Tue May 12 2026 Winds will become offshore around 15 knots this morning as a front continues to sag southward. Wind speeds will subside somewhat by early Wednesday morning, but may maintain an offshore component through Thursday before becoming onshore as high pressure moves east of the area. && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...RW LONG TERM....PG AVIATION...RW MARINE...RW